The manufacture of synthetic decorative coverings based on synthetic materials such as polyvinyl chloride (PVC), particularly for floors and walls, has been the subject of major developments in recent decades. These decorative coverings typically include a base material, for example, jute fibers, asbestos, non-woven glass fibers, synthetic foam and the like. A sheet or layer of PVC typically overlies the base. Finally, a desired decoration or pattern overlies the sheet or layer of PVC, which is usually protected by a transparent film covering or wear layer.
Several successive applications are typically carried out to produce the final decorative surface. The various components are typically applied using printing techniques. Each printing application generally requires a drying step, after which a transparent protective covering can be applied. In these printing processes, decorative components, commonly particles of a specific composition, are deposited through a rotary screen onto a substrate material.
Various apparatus have been developed to carry out these processes, for example, an apparatus is disclosed in German Patent No. 20 37 740 C3 to Knobel (“Knobel”) and another disclosed in U.S. Pat. No. 4,675,216 to DuForest et al. (“DuForest”). The apparatus disclosed in Knobel includes a rotating stencil roller and a rotating counter-roller mounted in a machine frame. A substrate material passes between the two rollers while being simultaneously printed. The stencil roller is perforated, while the counter-roller is smooth. A feeder pipe with openings for decorative components to pass through is positioned inside the stencil roller, with a worm shaft with a gear or screw to push the decorative components through the feeder pipe. A distributor roller with several squeegee ridges on its surface runs parallel to the feeder pipe. The decorative components are distributed along the length of the feeder pipe, pass through the openings in the feeder pipe onto squeegee ridges and are deposited onto the substrate through the stencil roller.
The apparatus disclosed by DuForest generally includes a roller having a mesh screen, a feed screw for distributing decorative components, and a hopper having a pair of blades inside. The screw feeds the decorative components along the hopper, while the blades regulate the flow of the decorative components through the mesh screen.
It would be advantageous to provide an additional rotary screen for depositing particles on a substrate. The present invention provides such screens, as well as methods for using the screens to apply particles to a substrate, and substrates prepared with the apparatus.